1. Field
The present disclosure relates to microvalve devices and methods of manufacturing the microvalve devices, and more particularly, to microvalve devices having a normally open type microvalve, in which an elastic film and a valve seat of the microvalve do not normally contact each other, and methods of manufacturing the microvalve devices.
2. Description of the Related Art
A clinical or environment-related sample may be analyzed by performing a series of biochemical, chemical, and mechanical processes. Currently, development of technologies for diagnosing or monitoring a biological sample is attracting increased attention. Due to its excellent accuracy and sensitivity, a developed molecular diagnosis method based on a nucleic acid is increasingly and broadly being used to diagnose infectious diseases and cancers, to study pharmacogenomics, and to develop new medicines. Microfluidic devices are commonly used to analyze a sample simply and precisely for the various purposes described above. In a microfluidic device, a plurality of sample inlets, sample outlets, microfluidic channels, reaction chambers, for example, are formed in a thin substrate and thus various tests may be simply performed on one sample.
From among the above-described microfluidic devices, microvalve devices having microvalves that control a sample and a reagent to flow to a desired location are currently developed and commercialized. For example, a microvalve device may include a thin elastic film interposed between two substrates, and a valve seat formed in a microfluidic channel of the substrates. In such a microvalve device, a microvalve is closed while the elastic film contacts the valve seat to prevent a sample from flowing through the microfluidic channel, and is open while the elastic film does not contact the valve seat to allow the sample to flow through the microfluidic channel.
In general, a microvalve device is manufactured as a normally closed type in which an elastic film and a valve seat normally contact each other. However, with the normally closed type, if a microvalve has not been used for a long time, an elastic film may naturally stick to a surface of a valve seat due to a chemical or physical reaction therebetween, and an initialization operation for separating the elastic film from the valve seat may be required. In addition, the elastic film may be permanently bonded to the valve seat in a process of permanently bonding the elastic film between the two substrates, and the microvalve may not operate normally. Accordingly, an additional process for preventing the elastic film from being bonded to the valve seat while the elastic film is permanently bonded between the two substrates may be required. Thus, the microvalve device may have a complicated manufacturing process and a high manufacturing cost.